Introduction
The response to stress is driven by two interdependent systems: the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), which regulate cardiac control, endocrine levels, and immune function (Tsigos et al., 2000).
Previous research suggests that regular exercisers show reduced responses to acute psychosocial stressors (Mücke et al., 2018). Nevertheless, it is currently unknown if the stress response in exercisers depends on the type of stressor and physiological marker of interest. Also, little research has directly compared male and female participants.
Understanding the specificity of the response is crucial for designing future research on exercise and stress.
This pilot study should clarify the feasibility of the presented design and methods to address this research gap.
Methods
We adopted a crossover design, exposing subjects to two laboratory-based stress tests in random, counterbalanced order. The Trier Social Stress Test (TSST; Kirschbaum et al., 1993) induces psychosocial stress, while the Maastricht Acute Stress Test (MAST; Smeets et al., 2012) incorporates additional physiological components by immersing one hand in ice water.
Young, healthy, physically active subjects (n = 12; 6 females, 6 males; age = 20-3 yrs) were invited to the laboratory twice, one month apart. Females were eumenorrheic and invited within the self-reported mid-luteal phase. Participants were asked to arrive well-rested and under standardized dietary conditions. After a 15-minute resting period during which baseline measures were taken, participants underwent the stress test. Subsequently, participants sat in a quiet room for follow-up sampling of heart rate (HR), serum blood (+0 min, +5 min, +25 min), saliva, and subjective stress via a 100 mm visual analog scale (VAS100; +0 min, +5 min, +10 min, +15 min, +25 min).
Free cortisol and HR were defined as primary markers for HPA and ANS activity, respectively, and analyzed using a [timepoint x test x sex] ANOVA followed by the Games-Howell. VAS100 was analyzed using continuous ordinal regression.
Results
HR was higher during the TSST than the MAST (∆ HR = 21.1 bpm, 95% CI [8.8, 33.4]). No sex differences for HR were found.
Sex differences indicate lower cortisol in females (g = 0.87, 95% CI [0.49, 1.26]), but no time- or interaction effects were found (p > 0.05).
VAS100 significantly increased following the stress tests. The MAST evoked higher VAS100 than the TSST (g = 0.46, 95% CI [0.13, 0.79]), and women reported higher levels of subjective stress than men (g = 0.62, 95% CI [0.29, 0.95]).
Discussion
While HR is a marker of ANS activity, the amount of movement during the interview phase might increase HR during the TSST. On the other hand, the VAS100 might reflect the physical pain experienced by the ice water and less so the psychosocial component. Despite increases in subjective stress, cortisol levels exhibited no change. This difference is in line with previous work hypothesizing even a protective effect of cortisol on subjective stress (Het et al., 2012).
We conclude that the design is promising for testing hypotheses concerning the physiological and subjective stress response during acute laboratory stress tests in an exercising population. As this is a pilot study, inferential statistics should be read cautiously. This study was designed to facilitate a larger-scale project with sufficient power.
References
Het, S., Schoofs, D., Rohleder, N., & Wolf, O. T. (2012). Stress-induced cortisol level elevations are associated with reduced negative affect after stress: Indications for a mood-buffering cortisol effect. Psychosomatic Medicine, 74(1), 23–32. https://doi.org/10.1097/PSY.0b013e31823a4a25
Kirschbaum, C., Pirke, K. M., & Hellhammer, D. H. (1993). The ’Trier Social Stress Test’—A tool for investigating psychobiological stress responses in a laboratory setting. Neuropsychobiology, 28(1–2), 76–81. https://doi.org/10.1159/000119004
Mücke, M., Ludyga, S., Colledge, F., & Gerber, M. (2018). Influence of regular physical activity and fitness on stress reactivity as measured with the Trier Social Stress Test Protocol: A systematic review. Sports Medicine, 48(11), 2607–2622. https://doi.org/10.1007/s40279-018-0979-0
Smeets, T., Cornelisse, S., Quaedflieg, C. W. E. M., Meyer, T., Jelicic, M., & Merckelbach, H. (2012). Introducing the Maastricht Acute Stress Test (MAST): A quick and non-invasive approach to elicit robust autonomic and glucocorticoid stress responses. Psychoneuroendocrinology, 37(12), 1998–2008. https://doi.org/10.1016/j.psyneuen.2012.04.012
Tsigos, C., Kyrou, I., Kassi, E., & Chrousos, G. P. (2000). Stress: Endocrine physiology and pathophysiology. In K. R. Feingold, B. Anawalt, M. R. Blackman, A. Boyce, G. Chrousos, E. Corpas, W. W. de Herder, K. Dhatariya, K. Dungan, J. Hofland, S. Kalra, G. Kaltsas, N. Kapoor, C. Koch, P. Kopp, M. Korbonits, C. S. Kovacs, W. Kuohung, B. Laferrère, … D. P. Wilson (Eds.), Endotext. http://www.ncbi.nlm.nih.gov/books/NBK278995/
Jean-François Toussaint, Martine Duclos, Juliana da Silva Antero
et al.
Objectives There is a lack of data on salivary sex hormones across the menstrual cycle (MC) or hormonal contraceptive (HC) cycle of elite athletes. We aimed to provide original data on salivary sex hormones (17β-estradiol, progesterone and free testosterone) in naturally menstruating female athletes with a regular cycle or irregular cycle and using combined HC. A secondary purpose was to compare these data with published data from the general population according to the menstrual status (MC or HC or irregularly menstruating).Methods 367 saliva tests were performed on 44 elite athletes during 6 months of follow-up to certify for cycle regularity. Athletes were grouped into regular MC, n=13; irregular MC, n=5; and HC, n=26. We compared salivary data of regular MC across six cycle phases (menses, mid-follicular, late follicular, early luteal, mid-luteal and late luteal phases) with published data from women with a similar MC or HC status from the general population.Results We provided salivary original data according to six sub-phases among elite athletes with regular MC. HC athletes showed lower salivary sex hormonal levels, markedly after the first week of active HC compared with regular MC. Athletes with irregular cycles do not show a progesterone rise from the first half to the second half of the cycle (Δirregular=0.38 (1.90), a rise detectable within regular MC group ΔregularMC=2.86 (2.88)).Conclusions We provided original data for salivary sex hormone levels in elite female athletes. These references may be valuable for research investigating MC or combined HC data, particularly in longitudinal follow-ups requiring repeated measurements.
The use of herbal medicinal products and supplements has increased during last decades. At present, some herbs are used to enhance muscle strength and body mass. Emergent evidence suggests that the health benefits from plants are attributed to their bioactive compounds such as Polyphenols, Terpenoids, and Alkaloids which have several physiological effects on the human body. At times, manufacturers launch numerous products with banned ingredient inside with inappropriate amounts or fake supplement inducing harmful side effect. Unfortunately up to date, there is no guarantee that herbal supplements are safe for anyone to use and it has not helped to clear the confusion surrounding the herbal use in sport field especially. Hence, the purpose of this review is to provide guidance on the efficacy and side effect of most used plants in sport. We have identified plants according to the following categories: Ginseng, alkaloids, and other purported herbal ergogenics such as Tribulus Terrestris, Cordyceps Sinensis. We found that most herbal supplement effects are likely due to activation of the central nervous system via stimulation of catecholamines. Ginseng was used as an endurance performance enhancer, while alkaloids supplementation resulted in improvements in sprint and cycling intense exercises. Despite it is prohibited, small amount of ephedrine was usually used in combination with caffeine to enhance muscle strength in trained individuals. Some other alkaloids such as green tea extracts have been used to improve body mass and composition in athletes. Other herb (i.e. Rhodiola, Astragalus) help relieve muscle and joint pain, but results about their effects on exercise performance are missing.
Mattia Bianchi, Liam Anderson, Thomas Brownlee
et al.
This study aimed to investigate the effect of a combined jump and sprint training program, two sessions a week for 6 weeks, on sprinting, change of directions (COD) and jumping performance in semiprofessional soccer players. Twenty soccer players were enrolled in this randomized controlled trial (age 20±2 years, body mass 74.3±5.9 kg). Players were randomized into two groups such as training group (TG, n = 10 players) or control group (CG, n = 10 players). Physical tests were performed before and after 6 weeks of training such as sprint 10 m, sprint 30 m, 505-COD test and standing long jump (LJ). The two groups performed the same training except for the combined jump and sprint training performed twice a week by TG. After 6 weeks of training, between-group analysis reported statistical difference in favor of the TG in sprint 10 m (p = 0.015, η 2 = 0.295, large), sprint 30 m (p < 0.001, η 2 = 0.599, large), in 505-COD (p = 0.026, η 2 = 0.154, large), and LJ (p = 0.025, η 2 = 0.027, small). These data indicate that combined sprint and jump training, when performed twice a week, for the duration of 6 weeks, in addition to the regular team training, can improve specific physical performance in male soccer players. This study has shown that a volume increment of 10% after 3 weeks of training can be a suitable training dose progression and that a combination of 64–70 jumps and 675–738 m of sprinting training per session can yield benefits in sprint, COD and jump performance.
Kelley Holladay, David Lardier, Fabiano T. Amorim
et al.
BackgroundCOVID-19 has affected mental health globally, increasing depression and anxiety. This study examined relationships between practicing COVID-19-related public health measures and depression and anxiety in young adult students.MethodsA sample of 755 undergraduate students 18–25 years of age at a large public university completed a cross-sectional survey in fall 2020 during the pandemic (response rate = 18.9%). The survey included demographic questions, anxiety and depression screeners (GAD-7 and PHQ-9), and questions on practicing public health measures (stay-at-home orders, quarantining, social distancing, etc.) since March 2020. Multivariate logistic regression was utilized to calculated adjusted odds between practicing public health measures and anxiety and depression.ResultsThe majority of respondents reported practicing public health measures; however, 53% experienced anxiety (GAD-7 score >10) and 57% experienced depression (PHQ-9 score >10) in the 2 weeks prior to completing the survey. Participants who quarantined had significantly higher odds of anxiety (AOR = 1.44; 95% CL 1.07, 1.96) and depression (AOR = 1.77; 95% CL 1.30, 2.41) than those who did not. Participants who self-isolated also had significantly higher odds of anxiety (AOR = 1.53; 95% CL 1.13, 2.08) and depression (AOR = 1.87; 95% CL 1.37, 2.56) compared to those who did not. Moving/changing living situations in response to the pandemic also increased odds of depression (AOR = 1.86; 95% CL 1.33, 2.60).ConclusionYoung adult undergraduate students experienced a high prevalence of anxiety and depression. Quarantining, self-isolating, and moving/changing living situations increased odds of anxiety and/or depression. The public health measures necessary for COVID-19 control and prevention may adversely affect mental health.
Safe water is still a major problem for travellers in many countries worldwide. In the last decade several new technical developments were made and more data exist about traditional procedures to produce safe water. This update includes such data with special regard to UV-C and held devices and SODIS.
Ida A. Heikura, Ida A. Heikura, Louise M. Burke
et al.
Objectives: To investigate diet-exercise interactions related to bone markers in elite endurance athletes after a 3.5-week ketogenic low-carbohydrate, high-fat (LCHF) diet and subsequent restoration of carbohydrate (CHO) feeding.Methods: World-class race walkers (25 male, 5 female) completed 3.5-weeks of energy-matched (220 kJ·kg·d−1) high CHO (HCHO; 8.6 g·kg·d−1 CHO, 2.1 g·kg·d−1 protein, 1.2 g·kg·d−1 fat) or LCHF (0.5 g·kg·d−1 CHO, 2.1 g·kg·d−1 protein, 75–80% of energy from fat) diet followed by acute CHO restoration. Serum markers of bone breakdown (cross-linked C-terminal telopeptide of type I collagen, CTX), formation (procollagen 1 N-terminal propeptide, P1NP) and metabolism (osteocalcin, OC) were assessed at rest (fasting and 2 h post meal) and after exercise (0 and 3 h) at Baseline, after the 3.5-week intervention (Adaptation) and after acute CHO feeding (Restoration).Results: After Adaptation, LCHF increased fasting CTX concentrations above Baseline (p = 0.007, Cohen's d = 0.69), while P1NP (p < 0.001, d = 0.99) and OC (p < 0.001, d = 1.39) levels decreased. Post-exercise, LCHF increased CTX concentrations above Baseline (p = 0.001, d = 1.67) and above HCHO (p < 0.001, d = 0.62), while P1NP (p < 0.001, d = 0.85) and OC concentrations decreased (p < 0.001, d = 0.99) during exercise. Exercise-related area under curve (AUC) for CTX was increased by LCHF after Adaptation (p = 0.001, d = 1.52), with decreases in P1NP (p < 0.001, d = 1.27) and OC (p < 0.001, d = 2.0). CHO restoration recovered post-exercise CTX and CTX exercise-related AUC, while concentrations and exercise-related AUC for P1NP and OC remained suppressed for LCHF (p = 1.000 compared to Adaptation).Conclusion: Markers of bone modeling/remodeling were impaired after short-term LCHF diet, and only a marker of resorption recovered after acute CHO restoration. Long-term studies of the effects of LCHF on bone health are warranted.
Diseases of the endocrine glands. Clinical endocrinology
Objective: The 3000-meter run is one of the most popular events among endurance and semi-endurance track runnings. Due to its special conditions, aerobic and anaerobic energy production systems can be used at the same time. The aim of the present study was to compare the effect of eight weeks of resistance and endurance trainings on physiological and functional factors and record of elite runners.
Methods: In this quasi-experimental study, 22 male elite runners were randomly assigned into the two groups of resistance (n=11) and endurance (n=11) trainings. The resistance and endurance trainings programe was performed for 8 weeks, 3 sessions per week, each for 55-60 minutes. Physiological and functional factors were measured at baseline and at the end of the study. Repeated measures ANOVA was used for within-group and between-group comparisons considering the significant level at P<0.05.
Results: The training led to significant improvement in heart rate, blood pressure, muscle strength, muscle endurance, balance and 3000-meter record in both groups. There was a significant difference between groups in the mentioned factors (P<0.05).
Conclusion: Both resistance and endurance trainings may have a positive effect on runners’ records and performance indicators.
Gustavo De Conti Teixeira Costa, Luan Galvão, Martim Bottaro
et al.
Background The aim of the present study was to analyse the effects of placebo on bench throw performance in Paralympic weightlifting athletes. Methods The study involved four Paralympic weightlifting male athletes (age: 40.25 ± 9.91 years, weight: 60.5 ± 8.29 kg, height: 1.60 ± 0.15 m) that visited the laboratory in three occasions, separated by 72 h. In the first session, the athletes were tested for bench press one repetition maximum (1RM). The other two sessions were performed in a randomized counter-balanced order and involved bench throw tests performed either after taking placebo while being informed that the capsule contained caffeine or without taking any substance (control). The bench throw tests were performed with loads corresponding to 50, 60, 70 and 80% of the bench press 1RM. Results According to the results, mean velocity (∆: 0.08 m/s, ES 0.36, p < 0.05) and mean propulsive velocity (∆: 0.11 m/s, ES 0.49, p < 0.05) at 50% of 1RM were significantly higher during placebo than control (p < 0.05). However, there were no difference between control and placebo for 60, 70 and 80% of 1RM (p > 0.05). Conclusion Our results suggest that placebo intake, when the athletes were informed they were taking caffeine, might be an efficient strategy to improve the performance of explosive movements in Paralympic weightlifting athletes when using low-loads. This brings the possibility of using placebo in order to increase performance, which might reduce the risks associated with ergogenic aids, such as side-effects and positive doping testing.
Diego A. R. Jaimes, Dennis Contreras, Alejandra M. F. Jimenez
et al.
Abstract Aim: This study aimed to compare the effects of linear periodization (LP) and undulating periodization (UP) of strength training on acceleration in skater children. Methods: Twenty-nine girls (9.67±1.29 years-old, 34.47±8.06kg, 1.39±0.13m) were distributed into two groups: linear periodization group (LPG, n=14) and undulating periodization group (UPG, n=15). Six levels of progressive training were designed based on activities such as multi-jumps, plyometrics, sled towing, and facilitated exercises. The training lasted 16 weeks, with a 1-h session on three non-consecutive days per week. The acceleration was recorded by digital videography following the major trochanter of the femur, at four moments and under two conditions: static (SS) and dynamic start (DS) in a rectilinear path. Statistical significance was set at 5%. Results: ANOVA indicated group*moment interaction in SS and DS for velocity (F3,81=7.883; p<0.001; pη2=0.226; F3,81=2.36; p=0.078; pη2=0.08-trend, respectively) and acceleration (F3,81=3.96; p=0.011; pη2=0.128; F3,81=2.92; p=0.039; pη2=0.098, respectively). Both groups increased velocity in SS and DS (UPG/SS: 1st=4.07, 2nd=9.75, 3rd=8.91, 4th=9.25m/s; LPG/SS: 1st=4.27, 2nd=7.13, 3rd=7.61, 4th=7.99m/s; UPG/DS: 1st=8.30, 2nd=8.73, 3rd=8.12, 4th=9.27m/s; LPG/DS: 1st=8.20, 2nd=8.31, 3rd=7.90, 4th=8.96m/s) and acceleration (UPG/SS: 1st=2.00, 2nd=8.69, 3rd=4.71, 4th=5.02m/s2; LPG/SS: 1st=2.37, 2nd=3.39, 3rd=3.68, 4th=4.12m/s2; UPG/DS: 1st=1.78, 2nd=1.97, 3rd=1.65, 4th=2.46m/s2; LPG/DS: 1st=1.67, 2nd=1.70, 3rd=1.48, 4th=1.93m/s2). Conclusion: Both strength training periodization protocols were effective in developing acceleration and velocity in girl skaters over 16 weeks; however, UP was more efficient than LP for improving acceleration.
Evaluation of motions is the basis for the diagnosis of human locomotor system disorders. Analyses are usually focused on the performance components of this system, i.e. on the skeleton and muscles. However, where comprehensive diagnosis is to be obtained, the motor system must be evaluated as a whole, without omitting any of its parts. So, evaluation of the control function is very important to body motion evaluation. The method that is normally used to evaluate the activity of brain is electroencephalography, which is superior to other brain activity-evaluating methods in many respects. However, EEG has also a major drawback, namely, it cannot precisely locate the activated and deactivated brain regions. This drawback can be avoided by using the sLORETA neurophysiological program, a tool that can transform EEG data to 3D brain images and finding application across a wide range of clinical branches of medicine – neurology, neurophysiology, psychiatry, physiotherapy and also in sports.